Either they blatantly photoshopped the photo or they actually made a room temperature super conductor. I can’t see how the could have made a subtle mistake that resulted in magnetic levitation at room temp without making a superconductor.
I really need someone to bring me down a notch. This is too exciting!
It seems this is worth cautious excitement, but don't get too excited yet.
For comparison, high temperature superconductors (in this context high temperature means tens of degrees kelvin) like the recently rather revolutionary ReBCO has critical current values measured in hundreds of thousands of amps per square centimeter. That would be a factor of a million.
This is clearly a very early result and until they have more insight into how it works (assuming it really works...) we'll have to be patient before we get more meaningful figures on the actual current carrying capacity of thicker conductors made out of this stuff. They were happy enough to be able to prove superconductivity at room temperature and normal pressure, clearly they are still a ways away from being able to line up a comparison with ReBCO with respect to current density. But surely that will happen soon if this is real.
>In 2008, Gozar et al. reported hightemperature interface superconductivity between metallic and insulating copper oxides(39). The thinner the layer, the greater the stress-inducing effect, the greater the strain, which seems to be the higher the superconducting transition temperature. Therefore, we argue that the stress caused by temperature and pressure brings a minute structural distortion and strain, which create an electronic state for superconductivity.
So the paper seems to confirm this, though the authors seem to be hopeful for general applications.
What we have here seems to be a clever trick to have ambient pressure superconductors by introducing crystal structure/microstructure stresses.
>But surely that will happen soon if this is real.
What I'm saying it that this is not so sure, may not be possible for a bulk material, may be insanely too expensive to be useful otherwise, and may be limited to very niche applications where milliamp superconductors might be useful (think sensors, microchips, and the like)
Sure is cool, but at the same time... cool your jets, eh?
As for cooling my jets: I don't think we'll see any real application of this in the next 10 years at a minimum, this stuff is the first step on a very long road towards commercialization. From the first mention of the photo electric effect (~1890) to practical (1956), affordable (1990's) solar panels took roughly a century.
https://en.wikipedia.org/wiki/Timeline_of_solar_cells
I hope that this superconductor, assuming it's real can be fast tracked given our much improved knowledge of materials and fabrication methods. But I'm realistic enough to realize how much work would still have to be done even if it is real. The road from the lab to the shelf is a long and expensive one and even in the best of scenarios I can't imagine anything on a timescale of less than a decade.
After all, there's no need for expensive cooling and the material looks reasonably cheap! (assuming it's real, of course..)
It's possible that they already normalized the figure, and if that's the case then 125 mA/cm^2 would be 'bad news' in the sense that even though the temperature and pressure are much better than other superconductors the critical current is much, much worse. But given the way the paper is formulated I'm not sure if that is a proper reading and it is very well possible that they are talking about a particular thin film sample (which would make it a small fraction of a square centimeter in cross section) and how much current they passed through that sample. In which case the situation would be much better already, especially if it turns out that the sample was extremely thin and/or narrow.
Too early to tell without more information.
It's on arXiv, which is a preprint journal, which means it has no peer-review; and is therefore generally less trustworthy (especially when the paper has no connection to a technical conference or is not being published elsewhere, and is in a non-computer science or mathematics field).
In addition to this, claims of room-temperature superconductors have been mired in controversy or otherwise proven false:
- http://www.superconductors.org/roomnano.htm (2004)
- https://www.nature.com/articles/nature.2012.11443 (2012)
- https://www.scientificamerican.com/article/a-superconductor-... (2018)
- https://www.quantamagazine.org/room-temperature-superconduct... (2020)
- https://forbetterscience.com/2023/03/29/superconductive-frau... (2022-2023)
Considering that many fraudulent claims of room-temperature superconductivity have gotten into Nature and other top-tier publications, I would wait for multiple independent recreations of the results in the paper.
The video headline says: "Magnetic Property Test of LK-99 Film".
That's how copper acts with a moving super magnet[0], so the video doesn't really show anything.
But still rather unconvincing.. especially if this is the best they could produce as a levitation proof video to publish.
Given the apparent size/strength of the magnets, you could probably replicate that with a silver coin
I agree with swamp40: the video you linked is not demonstrating the Meissner effect, and is just showing Lenz's law.
i.e. not like some of the ones you'd see here: https://www.youtube.com/watch?v=Vy9uWXgbKy0
But it still looks dependent on their being a NS pole at a corner.
That said...from this video https://sciencecast.org/casts/suc384jly50n I'm very suspicious of the behavior you see in the last few seconds where it gets pushed over to the corner and seems to fall right to the magnet That would be consistent with their being a ring magnet underneath the top magnet their, and once suitably over into the corner it loses the diamagnetic property because there's no N-S pole. The "seam" on what should be a bulk magnet in both videos that are out seems like an obvious problem.
So yeah...I think put me down for this is diamagnetism with pyrolytic carbon (the image in the paper also notably hides what you see in the video - that there's a seam on the magnet where it looks like it's a stack of two).
Other comments. https://news.ycombinator.com/item?id=36867758
Several physicists have spoken up and said this, and a few other tells distinguishes it from any conventional materials, which is why they made the video to begin with I'm sure.
That said I'm just parroting back the things I've picked up from this discussion.
If you move the magnet, the metal will also move since you're inducing a current and the fields from the eddy currents will react against the moving magnet.
That is super cool!
That said, I'm enough of a layman not to be able to connect this explanation to what I saw in the video.
Are you saying because it wasn't moving in "slow motion," we can rule out non-ferrous metals? Or are you saying the alternating movement/stillness of the magnet shows this?
All I see is the normal dampening and dragging effects that I show in my physics classroom.
I can tell it doesn't react to a magnet in ways that I'm familiar with (copper, iron, other magnets), but that's all the detail I can tell from the video.
Which is a weird thing to do when for superconductors you shouldn't need it, but for pyrolytic graphite levitation you would (to get an N-S pole).
But I'm just parroting back what the physicists in the thread have shared, so I might have some details wrong.
On reality, you would need a good computer with a large set of sound emitters just outside of the screen and a huge lot of tries. It would be a project for a small team and many months of work.
Or maybe a few transparent wires and less photoshop.
I do think the easiest way to fake a video like that would be to use a cool superconductor and change the atmosphere so nobody notices its temperature.
The bits and pieces of this certainly look like little are being genuine, so the new question is what non-obvious mistake could they be making?
And given the easiness in reproducing the study, there doesn't seem to be any point in fabricating it.
Like you'd question why someone would photoshop results[1] in a paper, because surely they'd have to realize they're fabricating data, but they go ahead and do it anyway.
The videos are convincing but are they of what they really purport to show? I agree - what would be the point of fabricating it. But weirder things have happened in the breadth of human experience.
[1] https://thenextweb.com/news/who-scientists-used-photoshop-to...
Nonscientific objections:
* it was published in a low h-index journal (not a scientific objection)
* poor formatting, misspelled title (not a scientific objection)
* patented and has a company (not a scientific objection)
* seems too simple, it has to be more complex than that, how could we have missed that? (not a scientific objection, also rather ahistorical)
I consider all of these pretty irrelevant given that the authors are not no-names and the actual paper makes clear claims, does exactly what everyone says you should be able to do if you have a real superconductor (show a video of it floating!) and makes replication easy. If it's straight up fraud it will be easy to discover.
There were also many pseudoscientific objections raised by field-adjacent people that I found uncompelling, responses from people actually in the field in parentheses:
* The first video looks like normal copper, the second like other diamagnetic materials or is otherwise unconvincing (not evidence against it being superconducting, at least one materials science lab had several members look at it and thought it looked legit).
* They are trying to hide the magnet structure somehow (the video shows it in clear view).
* The wafer isn't fully levitating or the way it falls is suspicious (not really unexpected given that the superconductive part is supposed to be present in only a few percent of the material).
Scientific objections I find more compelling made by people more familiar with the field, but more bourne of natural skepticism than disqualifying, with there being a lot of subtlety:
* both effects shown can be achieved in known ways by non-superconducting materials (but at the same time? would at least be a major material science advance in that case as it would apparently require diamagnetism ~ 150x as strong as graphite. Author who mentioned this said it would be "materials science magic" and I'm not sure why you'd rather believe in this than superconductivity given that neither have ever been seen before and it's consistent with sueprconductivty. Unless it's straight up fraud).
* Mesner effect graph don't go exactly to zero / happen exactly where you'd expect, maybe reflects a measurement error? (apparently, given the small % of the material that's supposed to be superconducting and material distribution, this isn't really evidence either way. not like we have other room temperature superconductors to compare it to).
* no max temperature where superconductivity vanishes measured, so is it really superconducting? (standard measurement devices only go up to what they reported, scientists seem very mixed about whether it would be easy to DIY measurement at higher temperatures for such a small current)
* not a similar mechanism to known good past "high-temperature" superconductors, and proposed explanation doesn't really make sense given slight deviations in pressure compared to what is in this substance (other scientists seem to disagree and think there could be something there, but it would also not be the first time something novel was discovered and worked for reasons totally different than those the scientists initially imagined)
Overall I find the quality of the objections really weak which increases (to me) the chances that there is something novel here, even if it's not superconductivity. That or it's obvious fraud and we'll know in like three days.
Fortunately if we're dealing with a real effect, this will be easily replicated and proven. But with the fixed perspective of a video, you can create a large number of apparent effects that look real in the constraints of the video format.
The biggest point in favor is that there's full reproduction instructions. I am eagerly waiting someone to try and pull this together separately.
Where I get hung up is, it's an extraordinary, world-changing claim. The standard of proof is very high (and while I could get access to a kiln, I can't get access to high pressure vacuum vessel on short notice).
* he and his team did discover a (probably) novel diamagnetic material. * it may or may not have interesting properties * however, it is not superconductive.
According to people who were able to more fully read the "real" paper, the key issue is that their measurements, if taken at face value (and not as due to, e.g., bad contacts with the material) suggest two contradictory things:
* the sample is extremely pure (due to the shape of the first graph).
* the sample has impurities causing it to not exhibit zero resistance, and not to exhibit "full" superconductive properties (i.e. having zero resistance under a magnetic field with increasing strength).
Additionally, since they were never able to measure Tc, they can't show the full Meissner effect as that requires heating up the sample to above its Tc first and then cooling it and flipping it, something you can't do with a diamagnet. By itself the fact that they didn't reach this temperature did not bother me, because I assumed that the senior authors were experts in superconductivity and had made sure that the material simultaneously exhibited other superconductive properties like zero resistance (or close enough when factoring in impurities). The fact that they were so focused on replication and the process was so simple made it unlikely to be fraud.
But, the fact that the first chart doesn't make sense unless the sample were completely pure, plus the lack of expertise they have with superconductors, indicates that it is much more likely measurement error on their parts, in which case it's not clear whether there's any evidence at all for superconductivity right now outside the diamagnetism. Given that there are many room temperature diamagnets known (albeit perhaps none as strong as this one?) and no room temperature superconductors known, this puts the odds that this isn't a superconductor at practically certain, IMO.
No, only ferromagnetic material would behave like that. Copper foil will also move in a moving magnetic field, and won't be attracted to a stationary magnet.
He should hold it in his hand for 10 seconds before the test.
https://en.wikipedia.org/wiki/Haruko_Obokata#STAP_cell_contr...
I don't really have an explanation other than they're simply crazy.
> And why fake it in the first place? I don't see the benefit.
That said, from the video it mentions the superconductor was applied as a film over copper. But wouldn't plain copper also exhibit this effect due to eddy currents? I fail to see how the (supposedly) thin film is affecting the plate in this experiment. I'm probably missing something and I hope someone can enlighten me.